Sleep structure and sleepiness in Chronic Fatigue Syndrome with or without co-existing Fibromyalgia – Source: Arthritis Research & Therapy, May 2008

Introduction: We evaluated polysomnograms of chronic fatigue syndrome (CFS) patients with and without fibromyalgia to determine if patients in either group had elevated rates of sleep disturbed breathing (obstructive sleep apnea or upper airway resistance syndrome) or periodic leg movement disorder.

We also determined whether feelings of unrefreshing sleep were associated with differences in sleep architecture from normal.

Methods: We compared sleep structures and subjective scores on visual analog scales for sleepiness and fatigue in CFS patients with or without co-existing fibromyalgia (n = 12 and 14, respectively) to 26 healthy subjects; none had current major depressive disorder, and all were studied at the same menstrual phase.

Results:

CFS patients had significant differences in polysomnograpic findings from healthy controls and felt sleepier and more fatigued than controls after a night's sleep.

CFS patients as a group had less total sleep time, lower sleep efficiency and less REM sleep than controls.

A possible explanation for the unrefreshing quality of sleep in CFS patients was revealed by stratification of patients into those who reported more or less sleepiness after a night's sleep (AM sleepier or less sleepy respectively).

Those in the sleepier group reported that sleep did not improve their symptoms and had poorer sleep efficiencies and shorter runs of sleep than both controls and patients in the less sleepy group;

Patients in the less sleepy group reported reduced fatigue and pain after sleep and had relatively normal sleep structures.

This difference in sleep effects was primarily due to a decrease in the length of periods of uninterrupted sleep in the AM sleepier group.

Conclusions:

CFS patients had significant differences in polysomnograpic findings from healthy controls and felt sleepier and more fatigued than controls after a night's sleep.

This difference was due to neither diagnosable sleep disorders nor co-existing fibromyalgia, but primarily due to a decrease in the length of periods of uninterrupted sleep in the patients with more sleepiness in the morning than on the night before.

This sleep disruption may explain the overwhelming fatigue, report of unrefreshing sleep, and pain in this subgroup of patients.